Final answer:
Option C, where insulin is given to one group of rats and no insulin to another to test effects on eating behavior, exemplifies a between-participants experiment, featuring distinct groups receiving different treatments.
Step-by-step explanation:
An experiment where a researcher administers insulin to one group of rats and no insulin to another group of rats to test the effect of insulin on eating behavior is an example of a between-participants experiment. In such an experiment, different groups of participants (or subjects in the case of animals) receive different treatments, allowing researchers to observe the effects of these treatments by comparing the groups. This is opposed to a within-participant design, where the same group is exposed to different conditions or treatments over time. The correct answer to which of the experiments listed is a between-participants experiment is option C: 'A researcher administers insulin to a group of rats and no insulin to another group of rats to test whether insulin affects the eating behavior of the rats.'
This design allows the researcher to control for individual differences across the groups that could confound the results. Random assignment is possible in such designs, which helps to ensure that each group is similar in key respects before any treatments are applied. These types of experiments can be highly effective in establishing cause-and-effect relationships.